High speed injector apparatus with dual throttle bodies

ABSTRACT

An apparatus for mixing a first fluid into a flow path of a second fluid, the apparatus comprising: a chamber enclosing the flow path, the chamber including a second fluid first inlet for receiving its respective fluid. The apparatus also includes a second inlet arranged downstream of the first inlet and receiving the first fluid, as well as an outlet arranged downstream of the second inlet for discharging a mixture of the first fluid and the second fluid. The second inlet flows into the flow path and is formed by a shared fluid injector mounted transverse to the axial direction that one fluid and the two fluid flows through its chamber. The flow path includes two respective throttle bodies, each of which is pivotally arranged inside the chamber and attached to opposed sides of the chamber for controlling the flow area of the flow path.

TECHNICAL FIELD

The present disclosure relates to an apparatus and a method for mixing afirst fluid with a second fluid, particularly for mixing steam intopulp.

BACKGROUND

This disclosure is an improvement to the apparatus and method forintroducing a first fluid into the flow path of a second fluid and useof such an apparatus disclosed in U.S. Pat. No. 9,427,716, issued 30Aug. 2016.

As used herein, fluid means a gas, a liquid, steam or a mixture ofthese. As used herein, fluid is also meant to include a systemcomprising a mixture of solid particles and a liquid or gas, where themixture has fluid-like properties. One example of such a system is asuspension, for example, a cellulose pulp suspension.

As used herein, introducing one fluid into the flow path of anotherfluid means injection, mixing, dispersion or other admixing of onefluid, which is also called the admixture fluid, into the flow path ofthe other fluid.

It is not unusual in industrial processes that fluids are mixed witheach other. In for example, the paper industry, it is not unusual thatprocess chemicals, for example, oxygen gas, chlorine dioxide or ozone,are introduced into a flow of pulp suspension. It is also common in thisindustry that steam is introduced into the flow of pulp suspension withthe purpose of heating the pulp suspension.

There are a number of previously known methods and apparatuses forintroducing one fluid into another fluid. One problem with these devicesis that they are relatively energy intensive and that they requirerelatively much maintenance.

When introducing one fluid into the flow path of another fluid, it isgenerally always desirable to obtain a mixing or dispersion of thefluids which is as effective and uniform as possible.

One objective when injecting one fluid into another fluid, particularlywhen injecting steam into pulp suspension, is to admix i.e., to mix anddisperse the added steam.

If the mixing or dispersion is not sufficient, there is a risk of steambubbles forming in the liquid or suspension, wherein said steam bubblesmay subsequently implode. These steam implosions cause pressure shocksin the liquid or suspension, which in their turn may propagate tomachine supports, apparatuses and other process equipment and causeknocks and vibrations, which can be so powerful that mechanical damageresults. This is especially a problem when a large amount of steam isadded to a cellulose pulp suspension and especially to a cellulose pulpsuspension of medium consistency. As used herein, a pulp suspension ofmedium consistency means a pulp suspension having a dry solids contentin the range of approx. 8-14%.

Accordingly, there is a need to maximize and improve the mixing anddispersion of the fluids in order to increase efficiency and minimizethe risks of damaging equipment.

SUMMARY

Disclosed is an apparatus for mixing a first fluid into a flow path of asecond fluid, the apparatus comprising: a chamber enclosing the flowpath, the chamber including a second fluid first inlet for receiving itsrespective fluid. The apparatus also includes a second inlet arrangeddownstream of the first inlet and receiving the first fluid, as well asan outlet arranged downstream of the second inlet for discharging amixture of the first fluid and the second fluid. The second inlet flowsinto the flow path and is formed by a shared fluid injector mountedtransverse to the axial direction that one fluid and the two fluid flowsthrough its chamber. The flow path includes two respective throttlebodies, each of which is pivotally arranged inside the chamber andattached to opposed sides of the chamber for controlling the flow areaof the flow path.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a first, preferred embodiment of anapparatus according to the invention.

FIG. 2 shows the apparatus of FIG. 1 in a side view.

FIG. 3 shows the apparatus of FIG. 1 in a top view.

FIG. 4 shows the apparatus of FIG. 1 in a view from behind.

FIG. 5 shows the apparatus of FIG. 1 in a side view, in cross-section,taken along the line A-A in FIG. 4, wherein a control unit of theapparatus is shown in greater detail.

FIG. 6 shows an axle and a flap of the control unit in cross-sectiontaken along the line B-B in FIG. 5.

FIG. 7 shows an embodiment where the apparatus comprises a secondconduit.

FIG. 8 is a schematic cross-sectional end view of an improved valveaccording to this disclosure, shown with a valve spindle in the form ofa cylinder shown in a valve closed position.

FIG. 9 is an end view of the improved valve shown in FIG. 8.

FIG. 10 is a perspective end view of the improved valve shown in FIG. 8.

FIG. 11 is an end view of the improved valve shown in FIG. 8, shown withthe cylinder shown in a valve open position.

FIG. 12 is a perspective end view of the improved valve shown in FIG.11.

FIG. 13 is a perspective view of a high-speed injector apparatusaccording to this disclosure.

FIG. 14 is a cross sectional view of the high-speed injector apparatusof FIG. 13, taken vertically along its longitudinal axis.

FIG. 15 is a cross sectional view of the high-speed injector apparatusof FIG. 13 taken along the vertical axis of the centrally located firstfluid inlet.

FIG. 16 is a perspective view of a portion of the centrally locatedsecond fluid inlet of FIG. 14.

FIG. 17 is a cross sectional view of another embodiment of thehigh-speed injector apparatus according to this disclosure, takenvertically along its longitudinal axis.

DESCRIPTION OF EMBODIMENTS

Disclosed is a high-speed injector apparatus intended to be used in aprocess plant for mixing a second fluid, in the form of steam, into theflow path of a first fluid, in the form of a cellulose pulp suspension,wherein the hot steam is intended for heating the pulp suspension to adesired temperature, for example, to a temperature that is suitable fora subsequent bleaching step. It will be appreciated, however, that theprinciple of the disclosure may be used for mixing other fluids, such asgases, such as oxygen gas, chlorine gas or ozone, or liquids, such aspH-adjusting liquids, chlorine dioxide or other treatment liquid, into apulp suspension. It will also be appreciated that the first fluid may beof another type than a pulp suspension, for example, process liquor.

The apparatus comprises a substantially parallelepipedic housing 1, forreceiving a pulp suspension from a first conduit 2 located upstream (seeFIG. 7), as well as for discharging the pulp suspension into a secondconduit 3 located downstream. The apparatus further comprises a supplymeans 4 for supplying steam to the flow of pulp suspension. Theapparatus further comprises a control unit 5, which ensures that thereis a suitable flow velocity in the pulp suspension when supplying thesteam, in order to avoid the occurrence of steam implosions.Accordingly, the control unit 5 ensures that the flow velocity of thepulp suspension exceeds a certain predetermined minimum value whensupplying the steam.

The housing 1 is delimited externally by an upper delimiting surface,constituted by a roof portion 6, lateral delimiting surfaces,constituted by side walls 7 and 8 and by a short side wall 9 locatedupstream and a short side wall 10 located downstream, and a lowerdelimiting surface, constituted by a base portion 11.

Internally, the housing 1 comprises a substantially parallelepipedicchamber 12, which is approx. 500-700 mm long, approx. 200-250 mm wide,and approx. 150-300 mm high. The chamber 12 exhibits a circular firstinlet 13 for receiving the pulp suspension from the first conduit 2disposed upstream, and a rectangular outlet 14 for discharging the pulpsuspension into the second conduit 3 disposed downstream. The firstinlet 13 is formed by an opening in the short side wall 9 locatedupstream and has a diameter of approx. 80-200 mm. Accordingly, the inlet13 has an area that is smaller than the cross-sectional area of thechamber 12. The rectangular outlet 14 is substantially equally large asthe cross-sectional area of the chamber 12.

Accordingly, the chamber 12 encloses a flow passage 44 for the pulpsuspension, said flow passage 44 extending from the first inlet 13 tothe outlet 14.

Furthermore, the chamber 12 exhibits an elongated second inlet 15 forreceiving the pressurized, hot steam from the supply means 4, said inlet15 opening into the flow passage 44. The inlet 15 is arranged in theroof portion 6 of the housing and is located approx. 100-150 mm from theoutlet 14 of the chamber. The supply means 4 connects to the secondinlet 15 from the top side of the roof portion 6. The second inlet 15 isarranged with its longitudinal direction transversely to the chamber 12and the flow passage 44, i.e. transversely to the flow direction of thepulp suspension, and extends across substantially the entire width ofthe flow passage 44. In other words, the second inlet 15 has a lengththat is substantially equal to the width of the chamber 14. The width ofthe inlet 15, i.e. its extension in the longitudinal direction of thechamber 14, is approx. 25-70 mm.

The base portion 11 exhibits an elongated recess 16, which extendstransversely to the longitudinal direction of the chamber 12 close tothe first inlet 13, and each of the side walls 7 and 8 exhibit arespective crescent-shaped opening 17, which connects to the recess 16at the ends thereof. A tubular cover 41 is fixedly disposed in theserecesses 16, 17, as is evident from FIGS. 5 and 6. The cover 41 has alength that exceeds the width of the housing 1, for which reason thecover projects outwardly on both sides of the housing 1, as is evidentfrom FIG. 1. The lower portion of the cover 41 protrudes below thechamber 12 and from the base portion 11 of the housing 1. As is mostclearly evident from FIG. 6, the central portion of the upper part ofthe cover 41 has been cut out, so that no part of the cover 41 projectsinto the chamber 12. Furthermore, this cut-out makes the axial space ofthe cover 41 accessible from the chamber 12 via the recess 16.

Two removable stoppers 45 and 56 are arranged in the base portion 11 ofthe housing 1 and in the cover 41. The stoppers 45, 56 enable rinsing ofthe housing 1 and the cover 41 in case of so-called plugging, i.e. thatthe pulp suspension clogs the housing 1 and the cover 41.

The supply means 4, for supplying the pressurized, hot steam to thechamber 12 and the flow passage 44 via the second inlet 15, comprises apipe flange 19 that connects to a steam conduit (not shown) for feedingpressurized steam to the supply means 4. Furthermore, the supply means 4comprises a pipe part 20, which exhibits a first end 21 and a second end22. The first end 21 connects to the pipe flange 19 and the second end21 connects to an elongated valve 23 of the supply means 4. The secondend 22 is compressed, as is evident from FIG. 1, making the pipe openingof the second end 22 elongated. The valve 23 connects to the secondinlet 15 of the chamber 12 via a screw joint 24. The valve 23 comprises,on the one hand, a pivotal valve spindle 25, exhibiting an elongatedlongitudinal gap 26 for passage of the steam, and, on the other hand, avalve spindle housing 27, enclosing the valve spindle 25. By turning thevalve spindle 25, the valve 23 can be adjusted to a fully open position,to a fully closed position, or to a desired position therebetween. Thegap 26 extends across the entire length of the second inlet 15. Theposition of the valve spindle 25 is controlled by a control means 28,which is disposed on the valve spindle housing 27 at one end of thevalve spindle 25.

The distance between the valve spindle 25 and the orifice of the inlet15 is relatively short, approx. 20-50 mm. This, together with the simplegeometry of the outlet, ensures that any pulp suspension, which may haveaccumulated in the inlet during an interruption of the steam supply,easily can be pushed out by the steam when the steam supply is resumed,which provides for good operating reliability.

The control unit 5 comprises a throttle body in the form of a flap orlip 29, a pivotal axle 37, two lever arms 48 and 49, and pivoting meansin the form of two pneumatic cylinders 50 and 51.

The axle 37 is pivotally arranged inside the axial space of the cover 41by means of self-lubricating bearings 43, as is evident from FIG. 6. Theaxle 37 is longer than the cover 41 and exhibits axle journals 46, 47,projecting outwardly through end plates 42, which are arranged at theends of the cover 41. Accordingly, the outer portions of the axlejournals 46 and 47 constitute projecting ends of the axle 37.

The flap 29 is arranged inside the chamber 12 and has the shape of asubstantially rectangular plate, having a thickness of approx. 25-35 mm.The flap 29 exhibits a top side 30, facing away from the base portion 11of the housing, a bottom side 31, facing toward the base portion 11 ofthe housing, two parallel long sides 32, 33, facing toward the sidewalls of the housing, a first end 34 or short side 34 located upstream,and second end 35 or short side 35 located downstream.

The flap 29 has its first end 34 fixedly connected to the pivotal axle37 by means of bolts 36 and extends, through the recess 16 in the baseportion 11, downstream in the flow direction of the pulp suspension. Thesecond end 35 of the flap 29 is free, and its connection to the top side30 is chamfered, as is evident from FIG. 5. The flap 29 has a lengththat is approx. 300-450 mm, i.e. slightly longer than the height of thechamber 12 and slightly shorter than the length of the chamber 12, sothat its free end 35, located downstream, is substantially aligned withthe second inlet 15.

The lever arms 48, 49 are fixedly disposed on the free ends of the axlejournals 46, 47 of the axle 37, at right angles to the longitudinaldirection of the axle 37. Accordingly, the lever arms 48, 49 rotatetogether with the axle 37 and the flap 29, when these are turned. Therespective lever arm 48, 49 abuts against one of said pneumaticcylinders 50, 51. In the shown embodiment, these pneumatic cylinders areconstituted by piston rod-free bellows cylinders 50, 51, which exhibitend plates 52, 53 abutting against the lever arms 48, 49. In the shownembodiment, the respective bellows cylinder 50, 51 is fixedly disposedon a respective side wall 7, 8 of the housing 1.

The flap 29 is pivotable between a lower end position, where the bottomside 31 of the flap abuts against the base portion 11 of the chamber 12,and an upper end position, where the free end 35 of the flap 29 abutsagainst the roof portion 6 of the chamber 12. The flap 29 has a widththat is substantially equal to the width of the chamber 12. Accordingly,when using the apparatus, the pulp suspension is forced to pass over thetop side 30 of the flap 29. Thus, the upper end position of the flap 29constitutes a fully closed position, where the flow passage 44 is fullyclosed, and the lower end position of the flap 29 constitutes a fullyopen position, where the flow passage 44 is fully open. Accordingly,when the flap 29 is located between its end positions, the flap 29 formsa constriction in the flow passage 44, where the flow area of the flowpassage decreases continuously from the end 34 of the flap 29 locatedupstream to the free end 35 thereof located downstream. Immediatelydownstream of the flap 29, i.e. directly downstream of its free end 35,the flow area of the flow passage 44 suddenly increases to its initialvalue, i.e. to the same value as directly upstream of the flap 29. Theinlet 15 opens near the free end 35 of the flap 29, and the steam isthus supplied in the region where the cross-section of the flow passage44 suddenly increases, which is advantageous for the mixing anddispersion of the steam into the pulp suspension.

While the pulp suspension passes over the flap 29, the pulp suspensionexerts a torque about the axle 37 on the flap 29, which tends to pushthe flap 29 down, i.e. to pivot the flap 29 clockwise about the axle 37in FIG. 5. Accordingly, the top side 30 of the flap 29 constitutes aguiding or diverting surface, which diverts the direction of flow of theflow path 44, with which surface the pulp suspension interacts toproduce said downward torque. The bellows cylinders 50, 51, in theirturn, are pressurized to a predetermined pressure. When they arecompressed, they exert a torque on the flap 29, via the lever arms 48,49 and the axle 37, which strives to push the flap up, i.e. to pivot theflap 29 anti-clockwise about the axle 37 in FIG. 5.

At a constant flow rate of the pulp suspension, the flap 29 adjustsitself to an equilibrium position, where the torque that the flow ofpulp suspension exerts on the flap 29 is balanced by the torque that thebellows cylinders 50, 51 exert on the flap 29. In other words, thebellows cylinders 50, 51 are adapted to continuously exert a torque onthe flap 29, which balances the torque that the pulp suspension exertson the flap 29 at every flow rate of the pulp suspension.

If the flow rate of the pulp suspension increases, the flap 29 is pusheddown, so that the smallest flow area of the flow passage 44, i.e. itsflow area at the end 35, increases. If the flow rate of the pulpsuspension stabilizes at this new, higher level, the flap 29 adjustsitself to a new equilibrium position, where the flow area of the flowpassage 44 at the end 35 is larger than in the previous equilibriumposition. If the flow rate of the pulp suspension decreases, the flap 29is pushed up by the bellows cylinders 50, 51, so that the flow area ofthe flow passage 44 at the end 35 decreases. If the flow rate of thepulp suspension stabilizes at this new, lower level, the flap 29 thusadjusts itself to a new equilibrium position, where the flow area of theflow passage 44 at the end 35 is smaller than in the previousequilibrium position. Accordingly, an increasing flow rate of the pulpsuspension causes the flow area of the flow passage at the end 35 toincrease, and a decreasing flow rate causes the flow area to decrease.

It will be appreciated that this controlling of the flow areacompensates for the decrease and increase, respectively, in the flowvelocity of the pulp suspension that results from a decrease and anincrease, respectively, of its flow rate. If for example, the flow rateof the pulp suspension decreases, also the flow velocity of the pulpsuspension in the region upstream of the flap 29 decreases, since theflow area in this region is unchanged. However, due to the decreasingpressure of the pulp suspension on the flap 29 in this situation, theflap is pivoted 29 upward and the flow area at the flap 29 decreases.This, in its turn, implies that the flow velocity of the pulp suspensionat the end 35 is maintained at substantially the same level as beforethe flow rate decrease. If the flow rate of the pulp suspensionincreases, an adjustment is effected in the other direction, i.e. due tothe increasing pressure of the pulp suspension on the flap 29, the flap29 is pushed down, the flow area above the flap 29 increases, and theflow velocity of the pulp suspension at the end 35 is maintainedsubstantially at the same level as before the flow rate increase.Accordingly, the flap 29 acts as a throttle body, which controls theflow area of the flow passage 44 while being actuated by the cylinders50, 51, so that the flow velocity of the pulp suspension is maintainedwithin a desired range. Accordingly, the control unit 5 ensures that adecrease of the flow rate of the pulp suspension does not lead to asituation, where the flow velocity of the pulp suspension at the steamsupply position falls below a level where the mixing of the steam risksbecoming so inadequate that there is a risk of damaging steam implosionsoccurring.

In addition to the fact that the bellows cylinders 50, 51 abut againstthe lever arms 48, 49 with a pushing force, the bellows cylinders 50, 51also dampen any pressure waves which may occur in the pulp suspension,for example, when the pulp suspension passes over the flap 29, or ifdamaging steam implosions still occur. Accordingly, the bellow cylinders50, 51 also constitute spring or damping means.

Accordingly, the flap 29 adjusts itself to an equilibrium position,where the flow of pulp suspension imposes a pushing force on the flap29, which is balanced by the force from the bellows cylinders 50, 51.Thus, the flap 29 is self-adjusting and its actual angle relative to thebase portion 11 is dependent on the magnitude of the pulp flow. Thepredetermined flow velocity range can be set by adjusting the abuttingforce of the bellows cylinders 50, 51 against the lever arms 48, 49,whereby the desired equilibrium position can be set. By increasing theabutting force of the bellows cylinders 50, 51 against the lever arms48, 49, the axle 37 is rotated so that the flap 29 is pushed up to a newequilibrium position. This implies that the cross-sectional area abovethe flap decreases, which causes the flow velocity of the pulpsuspension at the second inlet 15 to increase.

Accordingly, the apparatus is self-adjusting in that the control unit 5ensures that the flow velocity of the pulp flow at the second inlet 15is always sufficiently high to avoid, or at least reduce the occurrenceof steam implosions. The control unit 5 also ensures that an increase ofthe flow rate of the pulp suspension does not lead to an undesirablyhigh flow resistance across the apparatus.

It will be appreciated that the minimum allowable flow velocity of thepulp suspension at the steam supply position is dependent on a number offactors, for example, the concentration of the pulp suspension, thesteam flow rate, i.e. the amount of steam supplied, etc. As an exampleof a suitable flow velocity range when supplying steam to a pulpsuspension, it may be mentioned that, when mixing steam at a flow rateof approx. 2-20 kg/s into a pulp suspension of medium consistency, theflow velocity of the pulp suspension at the free end 35 should be withinthe range of approx. 30-35 m/s, if the embodiment shown in the figuresis used.

FIG. 7 shows an embodiment of the apparatus that is especiallyadvantageous when supplying steam to a pulp suspension. In thisembodiment, the apparatus comprises the second conduit 3 disposeddownstream of the chamber 12. The outlet 14 of the chamber 12 connectsto the inlet of the second conduit 3 by means of a pipe flange 55, whichis fitted to a pipe flange of the second conduit 3. The flow area orcross-sectional area of the second conduit 3 is larger than thecross-sectional area of the outlet 14. In a preferred embodiment, thecross-sectional area of the second conduit 3 is at least 50% larger thanthe cross-sectional area of the outlet 14. The area increase between thecross-sectional area of the outlet 14 and the cross-sectional area ofthe second conduit 3 occurs suddenly, in a single step. The length ofthe second conduit 3 is advantageously from two times all the way up toten times the diameter, or any other equivalent cross-sectionaldimension of the second conduit 3.

Since the cross-sectional area of the second conduit 3 is larger thanthe cross-sectional area of the outlet 14, the pulp suspension willdecelerate after the outlet 14 in those regions of the second conduit 3which are located radially outside the outlet 14, and be retainedagainst the inside surface of the second conduit 3. Therefore, a volumeof fibers will be built up successively by stagnant pulp, along theinside shell surface of the second conduit 3, which can absorb pressurewaves in the pulp suspension which may occur due to any steamimplosions. The pulp suspension in the middle of the second conduit 3,on the other hand, will continue at a high velocity through the secondconduit 3 to a subsequent third conduit 54, which has a diameter that issubstantially smaller than the diameter of the second conduit 3.

It will also be appreciated that the apparatus does not necessarily haveto comprise a conduit in accordance with the second conduit 3 of FIG. 7.The apparatus can of course be fitted to conduits of any dimensionswhatsoever which transport pulp suspensions.

It will also be appreciated that the throttle body may have a differentdesign than the above-described flap 29. The throttle body can forexample, be wedge-shaped.

Improved Valve of this Disclosure

FIG. 8 is a schematic cross-sectional view of an improved valve 80according to this disclosure, shown with a valve spindle 84 in the formof a cylinder shown in a valve closed position. The valve 80 comprises avalve spindle housing 27′ including an inlet 22′ and an outlet 15′, andthe cylinder 84. The cylinder 84 is open along a portion of alongitudinal axis of the cylinder 84 and rotatably mounted in the valvespindle housing 27′. The cylinder 84 in one position is positioned sothat the cylinder 84 completely obstructs the valve spindle housingoutlet 15′, not allowing any fluid to pass around the cylinder 84. Thecylinder surface is solid except for having openings 68 through aportion of the cylinder 84, so that when rotated to a first position,the solid portion of the cylinder 84 fully obstructs the valve spindlehousing outlet 15′, and when rotated to a second position (not shown),fluid can pass into the inside of the cylinder 84 and then through theopenings 68 and out of the valve spindle housing 27′.

The valve spindle housing outlet 15′ is defined by an opening having anedge 72, and the cylinder 84 is positioned closely adjacent the edge 72so that when the cylinder 84 is rotated (clockwise as shown in FIG. 8),the edge 72 clears away accumulated material (not shown) over thecylinder openings 68 on the outside of the cylinder 84.

Further, in the embodiment disclosed FIG. 8, the cylinder 84 is about ahalf cylinder, but in other embodiments, more or less of a cylinder canbe used.

More particularly, the cylinder 84′ of the valve 80′ shown in FIGS. 8and 9 is a whole cylinder, and has a fluid inlet in the form of spacedapart slots 92. In other embodiments (not shown), a single opening canbe used.

FIGS. 9 and 10 show the improved valve shown in FIG. 8 with the cylinder84′ in a valve closed position. FIGS. 11 and 12 show the improved valveshown in FIG. 8, with the cylinder 84′ shown in a valve open position.

Improved Apparatus of this Disclosure

Illustrated in FIGS. 13-16 is another apparatus 100 for mixing a firstfluid into respective flow paths 44′ and 44″ of a one fluid and a twofluid. Like numbers are used to identify similar elements servingsimilar functions to those found in the previous embodiment, and includea single or double apostrophe to indicate it is part of this furtherembodiment.

The disclosed apparatus 100 comprises a first chamber 12′ and a secondchamber 12″, each chamber enclosing a respective flow path 44′ and 44″.Each chamber includes a respective one fluid or two fluid first inlet13′ and 13″ for receiving its respective fluid, a respective secondinlet 115 and 115′ arranged downstream of the first inlet and receivingthe first fluid, as well as an outlet 14′ arranged downstream of therespective second inlet 115 and 115′ for discharging a mixture of thefirst fluid and the one fluid and the two fluid. Each flow path extendsfrom its respective first inlet to the outlet. Each second inlet flowsinto a respective flow path and is formed in a shared fluid injector 80″mounted transverse to the axial direction that one fluid and the twofluid flows through the respective chambers.

In the illustrated embodiment, the one fluid and the two fluid is asecond fluid. A splitter (not shown) separates the second fluid intoeach of the first inlets 13′ and 13″. By splitting the second fluidbetween the first inlets, the first fluid second inlet engages twice asmuch of the second fluid. In other embodiments, the one fluid and thetwo fluid could be different fluids. Further, each supply to the onefluid or two fluid first inlets can be throttled (not shown), andthrottled differently, if desired.

More particularly, as shown in FIGS. 15-16, the fluid injector 80′comprises a valve spindle housing 27″ including a first fluid inlet 22′and a respective first fluid outlet 115 and 115′, and a cylinder 84″open along a portion of a longitudinal axis of the cylinder 84″ androtatably mounted in the valve spindle housing 27′. More particularly,the spindle housing 27′ is cylindrical and has two first fluid outlets115 and 115′ formed by two openings on opposed sides of the spindlehousing. Each of the spindle housing first fluid outlets 115 and 115′form a fluid inlet in a respective flow path. In the illustratedembodiment, the cylinder 84″ includes two first fluid inlets 22′ and22″, one at each end of the cylinder 84″, and on the same side of thecylinder 84″. Each inlet is attached to its own respective first fluidsupply 4′ and 4″, as illustrated in FIGS. 13 and 15. This allows fortwice the volume of the first fluid to enter the cylinder. In thisembodiment, the first fluid is introduced into the cylinder through theopenings 22′ and 22″ in the cylindrical side of the cylinder 84″, but inother embodiments (not shown), the first fluid could be introduced intothe cylinder through the ends of the cylinder.

Further, as illustrated in FIGS. 14 and 15, the cylinder 84″ includestwo first fluid outlets formed by spaced apart sets of perforations 68′on opposed sides of the cylinder that extend along the longitudinal axisof the cylinder. This allows for the discharge of the first fluid intoeach of the respective one fluid and two fluid paths. In otherembodiments (not shown), other outlet shapes other than perforations canbe used.

The cylinder 84″ in one position is positioned so that the cylinder 84″completely obstructs the valve spindle housing outlets 115 and 115′, notallowing any fluid to pass around the cylinder 84″, the cylinder wallsbeing solid except for having the openings 68′ through a portion of thecylinder 84″, so that when rotated to a closed position, the solidportion of the cylinder 84″ fully obstructs the valve spindle housingoutlets 115 and 115′, and when rotated to an open position, the firstfluid can pass into the inside of the cylinder 84″ and then through theopenings 115 and 115′ and out of the valve spindle housing 27″.Intermediate positions permit variably limited flow through the valve80″.

An advantage of the disclosed valve over conventional valves is thatthere are two first fluid sealing surfaces. In other words, when thecylinder first fluid outlets 68″ are facing the enclosed portion of thespindle housing 27″, the valve 80″ is closed. Further, when the cylinderoutlets 68″ face the enclosed portion of the spindle housing 27″, thecylinder inlets 22′ and 22″ are also closed. This dual closure of thevalve 80″ helps to prevent the passage of the first fluid through thevalve when the cylinder is in the closed position.

Further, as illustrated in FIG. 14, each of the flow paths 44′ and 44″includes a respective throttle body 29′ and 29″, which is pivotallyarranged inside its respective chamber for controlling the flow area ofthe respective flow path; and respective pivoting means, for pivotingthe throttle body for the controlling of the flow area, the pivotingmeans being adapted to pivot the throttle body, so that the flow areadecreases with a decreasing flow rate of the second fluid and increaseswith an increasing flow rate of the second fluid in order to maintain aflow velocity of the second fluid at the second inlet within apredetermined range. More particularly, each respective throttle body isin the form of a flap 29′ and 29″ that has a first end that is pivotallyarranged in the chamber and a second end that is free, the free endbeing directly adjacent the injector second inlet 115 and 115′ so thatthe flap maintains the flow rate of the second fluid at the second inletin a desired range.

The flap first end is pivotally arranged, via a respective axle 37′ and37″, on a wall of the respective chamber opposite the first fluidinjector 80″. And at least one respective compressively loaded lever arm48′ and 49′ is arranged on the axle. The pivoting means comprises arespective pneumatic cylinder 50′ and 51′, which is adapted to producethe compressive load on the lever arm. Further, the flap 29′ and 29″ hasa width substantially equal to the chamber width.

In an alternate embodiment 100′, as shown in FIG. 17, instead of havingtwo second fluid inlets 13′ and 13″, a single second fluid supply 102and a single second fluid inlet 113 is provided with a single chamber112 and a single flow path 144 past the injector 80″ centrallytransversely mounted within the chamber 112.

The invention claimed is:
 1. An apparatus for mixing a first fluid intoa flow path of a second fluid, said apparatus comprising: a chamberenclosing the flow path, the chamber including a second fluid firstinlet for receiving the second fluid, a second inlet arranged downstreamof the second fluid first inlet and receiving the first fluid, and anoutlet arranged downstream of the second inlet for discharging a mixtureof the first fluid and the second fluid, the flow path extending fromthe second fluid first inlet to the outlet, the second inlet flows intothe flow path and is formed by a shared fluid injector mountedtransverse to a flow direction of the second fluid and the mixture ofthe first fluid and the second fluid through the chamber, the flow pathincluding two throttle bodies, each of the throttle bodies is pivotallyarranged inside the chamber and attached to opposite sides of thechamber for controlling the flow area of the flow path; and pivotingmeans for pivoting each throttle body for said controlling of the flowarea, the pivoting means being adapted to pivot the two throttle bodiesso that the flow area decreases with a decreasing flow rate of thesecond fluid and increases with an increasing flow rate of the secondfluid to maintain a flow velocity of the second fluid at the secondinlet within a predetermined range, wherein each respective throttlebody is in the form of a flap that has a first end that is pivotallyarranged in the chamber and a second end that is free, the second endbeing directly adjacent the second inlet so that the flap maintains theflow rate of the second fluid at the second inlet in a desired range. 2.The apparatus according to claim 1, wherein the fluid injectorcomprises: a valve spindle housing including a first fluid inlet and afirst fluid outlet, and a cylinder open along a portion of alongitudinal axis of the cylinder and rotatably mounted in the valvespindle housing, the cylinder being positioned in one position so thatthe cylinder completely obstructs the valve spindle housing outlet, notallowing any fluid to pass around the cylinder, cylinder walls of thecylinder being solid except for having openings through a portion of thecylinder, so that when rotated to a closed position, the solid portionof the cylinder fully obstructs the valve spindle housing outlet, andwhen rotated to an open position, the first fluid can pass into theinside of the cylinder and then through the openings and out of thevalve spindle housing.
 3. The apparatus according to claim 2, whereinthe valve spindle housing outlet is defined by an opening having anedge, and the cylinder is positioned closely adjacent the edge so thatwhen the cylinder is rotated, the edge clears away accumulated materialover the cylinder openings on the outside of the cylinder.
 4. Theapparatus according to claim 1, the first end being pivotally arranged,via an axle.
 5. The apparatus according to claim 1, wherein each of theflaps has a width substantially equal to the chamber width.